During a material welding process, molten material may flow from the location where the weld is initiated to an area outside of the zone at which the welded components are bonded to one another. Sometimes referred to as “flash”, the molten material can harden or freeze in an undesirable location. In some instances, weld flash exposed in an undesirable location can be removed; however, in some assemblies, weld flash can migrate to an enclosed or otherwise inaccessible area so that removal of the weld flash is difficult if not impossible. In some situations, the presence of weld flash can be problematic.
For example, in a known automobile cooling system a crossover tube is provided in a manifold assembly in which the cross over tube is overmolded and substantially inaccessible in the final assembly. The crossover tube includes an opening in which a cap is welded, with the weld being initiated from the outside of the tube. It is known to provide essentially flat confronting surfaces on the cap and on the receiving end of the cross over tube, to define a zone or area of overlap in which the weld joint is established. The welding process is initiated from outside of the tube. During the welding process to affix the cap in the tube, melt occurs, and resultant weld flash is pushed away from the weld, causing it to flow along the confronting surfaces toward the inside of the tube. If the weld flash migrates sufficiently far, the weld flash can become exposed on the inside of the crossover tube. Weld flash exposed in the crossover tube is considered a contaminant in that the weld flash can break loose and can be washed into the engine by the coolant that flows through the interior of the crossover tube. Accordingly, the flow of weld flash into the inside of the crossover tube is an occurrence to be avoided.
What is needed in the art is a way to manage and contain the flow of weld flash, so that the weld flash does not migrate to an undesirable location in the welded assembly.